


Forbidden

by Unexisted_user



Category: Yuri!!! on Ice (Anime)
Genre: Dark, Gender Bender, Incest, M/M, Male!Mari, Masturbation, Mentioned of sex between male and male, OOC, noncon, unbetaed
Language: English
Status: Completed
Published: 2017-02-14
Updated: 2017-02-14
Packaged: 2018-09-24 14:08:42
Rating: Mature
Warnings: Rape/Non-Con, Underage
Chapters: 1
Words: 1,751
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9751343
Author URL: https://archiveofourown.org/users/Unexisted_user/pseuds/Unexisted_user
Summary: Mari had always been in love with his only sibling, Yuuri. The older sibling of Katsuki tried to hold his feeling down under the disguise of brotherly love. Until he heard that Yuuri was in love with some foreign man and already had an intimate relationship that his patience and control snapped.





	

**Author's Note:**

  * For [ayaMASO](https://archiveofourown.org/users/ayaMASO/gifts).



.

.

Soft, silky black hair as dark as the midnight sky, warm brown chocolate eyes that shone like a jewel in the middle of Sahara desert, cute button nose and red, plump moist lips. Skin as fair as the white of snow and small, slender built with curvy hips and firm, round backsides.

And it all described one person.

Yuuri Katsuki.

Lovely, desirable and delicious.

Mari groaned as he came into his hand. He stared at the white substance on his hand and tsked. Once again, he had lost his control and used his baby brother as a masturbation material for him. Wrong. Very wrong. He knew that he was not supposed to do that and yet he could not stop himself. Day after day, he found out that he loved his baby brother more than he should be. It was a love deeper and different than a love siblings or family should share.

It was not like agape at all.

It was more eros.

The sexual kind of love.

.

.

"Yuu-chan, what are you doing here?" Mari immediately sat up on his bed when the younger boy jumped in his bed and immediately tackled the older boy.

"Oof!" Mari felt his breath left his lungs. He looked down only to see a mop of messy black hair. "Yuu-chan, what?"

"You know what, Big Bro?" Big brown eyes stared up at him in admiration.

"Hm... what's it?" Mari smiled down at his adorable baby brother as he carded his fingers through the soft black tresses.

"I got A's in my Mathematics and Science tests. Its all thanks to your tutoring." Yuuri nuzzled on the older boy's chest and rested his head there.

"Congrates for getting A's in your tests, Yuu-chan." The older sibling smiled, letting Yuuri do whatever he wanted on him. Yuuri was his and he would even let the boy stab him to death.

That was the extent of his live for his baby brother.

"Also..." this time Yuuri's voice was softer and shy. The boy kept his head on the firm, hard chest below him as he fiddled with the fabric of Mari's shirt.

"Hm?"

"I-I think I'm in love..." Yuuri immediately buried his face into the heaving chest.

I-I think I'm in love...

I-I think I'm in love...

I-I think I'm in love...

Mari felt his world darkening and his chest felt heavy and his throat constricted. He gasped, hands on his throat as he tried to breath from his opened mouth and flaring nose. He vaguely realised as Yuuri's panic voice rang in the room and the footsteps of their parents filled his room. He heard someone talked to his ear and the soft voice was trying to bring him back to the world of conscious.

"Mari Big Bro, are you okay?"

Mari blinked his eyes and finally after a few minutes of calming, he felt his focus and control came back.

"Mari, are you okay now, dear?"

He turned his head at his mother's way and smiled lightly. He nodded his head. "I'm fine, mom." Mari then turned to look at his family's worried faces. "Sorry I worried you guys. What happened to me?"

Toshiyo shook his head and sighed. "You had a panic attack." The elder male frowned and asked. "What happened, Mari?"

He frowned and shook his head. He felt his world darkened and he had difficulty breathing. It was something important that he could not accept and had him went into a panic attack.

"Sorry I forget about it." He closed his eyes. "Sorry mom and dad. I want to sleep." Mari turned around as he faced the wall.

"Good night, Mari." He heard both his parents greeted him and the door to his bedroom closed shut.

He was about to get shut eyes when he felt the bed dip and thin arms wrapped around his waist. He opened his eyes and turned around. "Yuu-chan."

"Sorry, Big Bro."

"Why are you apologising?"

"I don't know." The younger boy tightened his arms around the college student. "I just think I did something wrong."

"..."

"Sorry Big Bro." Yuuri buried his face into the hard chest. "Good night, I love you."

Mari closed his eyes and buried his nose into the messy dark locks. His heart swelled in happiness and felt the heavy burden from before lift, leaving his chest light. He smiled and wrapped his own arms around the smaller male. "Good night baby bro. I love you too."

.

.

For a few weeks, Mari was busied with college activities and assignment. It was the normal occurences in his life and the only thing changing was Yuuri went to his room to sleep with him, everyday. The boy had shown a strong protest when Mari said he was fine and he would never go into panic attack again. Also that was his first panic attack. Never in his life he was having any anxiety or panic attack. So, the thing that trigger it would be too serious for him to fell into an attack.

It was already two months since then.

He sighed and went to find Yuuri since it was almost dinner and the boy had not come out from his room.

He was near the room and about to knock when he heard soft voice of his brother talking to someone. Mari opened the door slightly and peered into the younger boy's room. He saw Yuuri talking with hushed voice over to a phone receiver. He listened in.

"I know, I'll eat after this."

"..."

"Hm... you too, Victor. Take care of your body well. You have competition coming this May and don't forget to eat."

"..."

"Yes, I'm fine. My body is fine as well." Yuuri blushed as he traced the bedspread. "You were gentle and considerate. So, it did not hurt that much.

"..."

"You don't have to worry, Victor. I can take care of myself very well."

"..."

"I know." Yuuri smiled softly and tightened his hold on the phone. "I love you too. Good night "

The youngest Katsuki ended his call and sighed before he walked to the door. He was surprised when he saw Mari was there, looking, staring at him expresionless. The boy flinched under the heated stare, making him fidget on his place. "Big bro? What are you doing here?"

Mari forced a smile on his face and shook his head. "I was about to knock on your door but it seemed I didn't have to." He turned around and walked to the way to the dining room. The younger boy followed behind him. He still could not believe what he had heard. From what he heard, Yuuri was in a relationship with a boy; the name Victor could only belonged to a male. And it seemed they were already involved in an intimate relationship based on Yuuri saying that his body was fine.

He felt his body burned with anger and jealousy.

He just took his eyes off Yuuri for a while and some pest had taken what was his.

Yuuri was his baby brother and he would make sure that the boy knew and understood what was him to Mari.

.

.

That night when everyone had sleep, Mari walked to his brother's room. The boy decided that very night to not come into Mari's room to sleep since he had many homeworks to do. He slowly opened the closed door and grinned as he saw his baby brother sleep on the desk. His chubby cheek plastered on the book. Drools wetted the paper.

He chuckled and softly closed the door.

Tonight, he would make Yuuri his.

And here he was, lifting the sleeping boy in his arms as he carried him to the bed. He put him down. He then carefully removed the shirt, pants and underwear, leaving Yuuri naked. He stared at the naked body, feeling his desire rise and his pants tightened uncomfortably. He hastily removed own clothing, leaving him in his tight boxer briefs. He groaned and palmed his erection.

He was hard.

So hard that it was starting to hurt.

"Ugh..." he groaned as he stepped out of his underwear, finally releasing his hard length. The sex organ stood proudly as he stared at the sleeping boy.

So pretty.

So very beautiful.

And it was all going to be his tonight.

He would clean Yuuri's sullied body from that man's touch.

And he would be the one to paint and mark the deepest, intimate part of his love's body.

Mari stepped onto the bed, hovering above the naked sleeping boy as he caressed and touched anywhere he could. He smelt and licked the pink nubs that bloomed beautifully on his Yuuri's chest. "Ngh..." Yuuri moaned in his sleep. Mari stopped for a while and looked up. Good. His baby brother was still asleep.

He continued his path down the slender body. Memorising and worshipping the beautiful creation of God. Oh, how low he had fallen to make a grave sin that could not be forgiven. He sighed in relief and ignorance. The sin. He knew he had made the biggest sin but he could not help it. He loved Yuuri too much and he could not control his desire for his baby brother

He would be damned to hell.

But he did not care.

Nuzzling into the coarsed hair on above the limp organ, Mari took a deep breath. He almost came as musk scent and Yuuris unique smell filled his nostrils. He groaned and felt the impatience rolling off him. Taking a lotion on the bedside table, he covered and wetted his three fingers before he lifted Yuuri's legs and poured some more lotion on his pink rose bud.

Yuuri groaned in his sleep. His lids moved as he frowned slightly.

Mari ignored that. Without waiting, he eased one finger into the tight hole, pushing in and out before he added the second and third finger. By the time, he was finished with the preparation. He lubed his erection and hissed when the cold substance covered his hot, hard length.

But it was at that time when Yuuri moaned and finally opened his eyes. "...Mari?" He asked, voice filled with sleep.

Mari smiled down at him and spread the sleepy boy legs further. Leaning down, he whispered into the dazed boy's ear, "I love you, Yuu-chan," before he drove in one hard thrust into the tight entrance.

Eliciting a silent, surprised gasp from his unwilling partner.

"Happy Valentine's Day, baby bro. I love you."

The End 

**Author's Note:**

> I hope you do enjoy my Valentine gift for you ayaMASO. Sorry for posting it so late. I just have finished writing this.
> 
> For other readers, I hope you enjoy it too. You guys could imagine what happens afterward.


End file.
